The case began in 2010 when a Monroe County deputy pulled over Clayton Williams of Warrens. Williams' blood alcohol content was 0.248 percent, more than three times the state's 0.08 percent limit for driving.

Williams pleaded guilty in 2011 to a seventh offense of operating while intoxicated and asked for probation. Judge J. David Rice said the sentencing statutes for seventh-, eighth- and ninth-offense are murky. The statutes say the confinement portion of any bifurcated sentence — a sentence that includes both prison and extended supervision — for those repeat offenses must include at least three years in prison. But they don't expressly state that a judge must impose such a sentence.

Rice told Williams he believed the statutes required him to sentence him to at least three years in prison. The judge gave him that time as well as three years on extended supervision.

Williams turned to the 4th District Court of Appeals, arguing Rice made a mistake. The appellate court sided with Williams, ruling the statutes clearly don't require a judge to impose three years in prison and Williams should be re-sentenced.

The Supreme Court reversed the appellate ruling in a 7-0 decision Tuesday, saying Williams isn't entitled to re-sentencing. Justice David Prosser wrote that the statutes are ambiguous but the history of their development shows they're meant to ensure seven-, eight- and nine-time offenders spend at least three years in prison.

Prosser wrote that a Legislative Reference Bureau analysis of the 2009 bill that created the bifurcated sentence language for seventh-, eighth- and ninth-offenses stated the measure requires any of those offenders to serve at least three years in prison and a 10-time offender and beyond to serve four years. And a report from the Joint Review Committee on Criminal Penalties also supports an interpretation that judges must impose a bifurcated sentence with at least three years in prison, he said.

The mandatory three years also fits with Wisconsin's system of gradually more severe punishment for chronic offenders, he added.

Williams' attorney, public defender Steven Grunder, didn't immediately return a message. A spokeswoman for the state Department of Justice, which brought the case to the high court, said in an email to The Associated Press that agency attorneys were pleased the court provided needed guidance for judges and lawyers.